dude alot of other countries in europe and the middle east already have cars that run on natural gas.
these cars where made to run on gasoline but the put a natural gas tank in there trunk and yo buy this gas reductor thats like 100$ and blast that gas straight into your engine(you can put a switch in the car to switch from natural gas to gasoline)
hell you could even do it on a HUMMER!!!!
they just dont crash like the ppl in the US do....